How to use this checklist

You do not need to become a full-time email expert to avoid obvious spam triggers. The idea is simple: check a few basics in four areas – setup, list, content and behaviour – before big sends.

If you cannot fix everything at once, start with setup and list. Even average content works better on a clean, authenticated sending base.

The 10-point spam prevention checklist

# Check What to look for
1 Domain authentication SPF, DKIM and DMARC are set correctly for the domain you are sending from.
2 Sending reputation No obvious blacklists, bounce spikes or complaint spikes on your IP/domain.
3 List quality Old, inactive or purchased contacts removed; new contacts are permission-based.
4 Unsubscribe & footer Clear unsubscribe link and sender details in every email.
5 Subject line Honest, relevant and not over-promising; matches the content inside.
6 Content balance Reasonable image-to-text ratio and not packed with too many links or buttons.
7 Sending volume pattern No sudden jump from “almost nothing” to lakhs of emails in one day.
8 Sender identity From-name and address are consistent and recognisable to your audience.
9 Test sends Tested on a few inboxes and devices to catch obvious issues.
10 Engagement plan Campaign is going to people who opened or engaged recently, not just everyone in one go.

1. Setup: can mailbox providers trust you?

Check 1 – SPF, DKIM and DMARC

These three records tell inbox providers that your SMTP or email service is allowed to send for your domain and that messages are not forged.

  • Confirm that SPF includes the IPs or services you actually use.
  • Ensure DKIM is enabled and signing for your sending domain, not a random default.
  • Start with a basic DMARC policy, even if it is initially set to only monitor.

Check 2 – reputation, bounces and complaints

Even with correct records, a history of hard bounces and spam complaints makes filters cautious.

  • Keep hard bounce rates low by removing bad addresses after each send.
  • Watch complaint rates; if many people mark you as spam, pause and review targeting.
  • If you changed SMTP or tools recently, warm up gradually instead of sending full volume on day one.

2. List: are you sending to people who still care?

Check 3 – remove old and risky contacts

A large list is not always a valuable list. Inactive or purchased contacts drag engagement down and create more spam signals.

  • Remove addresses that bounced hard earlier.
  • Segment people who have not opened in months and either pause or run a gentle re-engagement first.
  • Avoid using scraped or bought lists for direct campaigns; they cause problems quickly.

Check 4 – clear unsubscribe and identity

Making it easy to opt out reduces the chance that frustrated subscribers click “spam” instead.

  • Have a visible unsubscribe link in the footer of every campaign.
  • Include basic business details: brand name, website and location.
  • Use a consistent from-name like “Brand Name” or “Rohit from Brand Name”, not something random each time.

3. Content: are you triggering filters by accident?

Check 5 – subject line reality check

Filters and humans both dislike misleading subjects. Over-promised subjects with generic templates are a common complaint trigger.

  • Describe the main value of the email honestly.
  • Avoid clickbait that has nothing to do with the body content.
  • Test calmer, specific subjects instead of shouting in all caps.

Check 6 – images, links and layout

Very image-heavy emails with almost no text, or emails stuffed with links, often look suspicious to spam filters.

  • Ensure there is enough real text for filters to understand the message.
  • Use a reasonable number of links, ideally pointing to your own domains.
  • Keep the file size of images sensible; do not embed giant banners everywhere.

Check 7 – mobile and basic clarity

If people open, cannot read properly on mobile and close immediately, that behaviour still sends a signal.

  • Use responsive templates so content fits on phones.
  • Break content into short paragraphs with clear headings and one main call-to-action.
  • Test on at least one mobile device before major campaigns.

4. Behaviour: how and when you send

Check 8 – avoid sudden volume spikes

Going from almost zero to lakhs of emails in one shot is a classic pattern for suspicious traffic.

  • Ramp up volume gradually, especially on new domains or IPs.
  • Split big lists across a few days instead of one blast if you have been quiet for a long time.

Check 9 – send to engaged first

Inbox providers watch how people react. If your most engaged segment reacts well, it helps the rest of the send.

  • Send first to people who opened or clicked in the last 30-90 days.
  • After seeing stable engagement, extend to slightly colder segments.
  • For very old segments, consider a separate re-introduction instead of jumping straight into heavy promotion.

Check 10 – test before you send big

Quick tests catch broken links, layout issues and accidental mistakes that would otherwise cost you a whole campaign.

  • Send test emails to a few internal addresses on different providers (Gmail, Outlook, etc.).
  • Click every main link and button once to confirm they work.
  • If you use a dedicated SMTP platform, glance at logs after the test to confirm everything looks normal.

What to do if you are already in spam

If you suspect many emails are landing in spam today, do not panic-send more campaigns. Step back and fix the basics in this order: setup, list quality, then content and schedule.

  • First, fix authentication and obvious technical problems.
  • Second, clean the list and reduce who you are emailing temporarily.
  • Third, send a few helpful, low-sales emails to engaged contacts before resuming heavy promotions.
If you want another pair of eyes on your setup and lists, you can share your domain, typical volume and one or two recent examples. We can then suggest what to fix first.
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